Not at all. SMFA was originally pitched as Uncle Grandpa for CN's Cartoonstitute. The network suggested that they make a spinoff instead. It didn't last long and UG got his own series eventually.
Anyway, I'm not sure if this would count (since it never went beyond the pilot), but Craig Bartlett's Party Wagon was pitched for Adult Swim. It wound up airing once on Cartoon Cartoon Fridays, then was never seen again.
I knew that I was going to get this kind of response at some point. Basically, Mike Lazzo was trying to bring a wide range of diversity in the lineup for [adult swim] by recruiting new shows. One day, he was listening to Andre 3000's music and decided to get him to make a show. He agreed to it, but there was no decision as to what the show's premise would be. They just knew that it had to move like the music. When Andre 3000 was touring Atlanta, Georgia, he suddenly realised what he wanted to do-- make a show about a music teacher and his pupils in Atlanta-- and he and Lazzo immediately knew that it had to be for children. Class of 3000 would be the last show greenlit under Lazzo before his presidency at [adult swim].